*Samples were received from natural heritage centers, wildlife rescue organizations, and private veterinary practices.
†Letters are used in a wide range of combinations to suggest a species’ seasonality. R, resident; R(m), resident and partial migrant; P, passage migrant (i.e., spring, autumn, or both); W, winter visitor; S, summer visitor or summer resident. Numbers (1–5) are used to express estimated abundance since 1980: 1, numerous (>100,000 records or individuals); 2, rather common/locally common (10,000–100,000 records or individuals); 3, fairly common (1,000–<10,000 records or individuals); 4, uncommon or rather local (100–<1,000 records or individuals); 5, scarce or very local (recorded annually, with ≥100 records from 1980 to the present time and <100 records estimated to occur annually). For less regularly recorded species, V followed by a number (1–5) indicates all known records (from 1980 to the present time): V1, probable annual (25–99 records or individuals); V2, recorded scarcely annually, or less than annually (10–<25 records or individuals); V3, ≥10 records, n); V4, species last recorded >10 years ago; V5, species added to the Birds Korea Checklist since the past update (starting in October 2007). On occasion, these codes are also used with a prefix (e.g., W, S) to indicate that more abundant species also occur more rarely in a given season (between 1980 and the present time). For example, S3, WV3 indicates that a species that is fairly common in summer has also been recorded <10 times in mid-winter between 1980 and the present time. This manner of measuring migratory status (seasonality) and abundance is followed by The Birds Korea Checklist: 2009 (6).